I shot a grizzly and had complete pass thru, but with a little more poundage than you are shooting. As everyone said, there is not a lot of heavy bone structure in a bear. Just pick a spot tight to the front leg and let her fly.
I shot my grizzly at 20 yards and it ran back on me, but dropped at 10 yards. I took the heart out of it. Was so fast, I couldn't even get another out of my bow quiver.